The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from t...The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from the sprite-producing lightning were measured at five ground stations, making it possible to locate and identify the individual causative lightning discharges for different elements in this dancing sprite event. The results of our analyses indicate that the sprites were produced above the trailing stratiform region of the MCS, and their parent strokes were located mainly in the peripheral area of the stratiform. The lateral offset between sprites and causative strokes ranges from a few km to more than 50 km. In a particularly bright sprite, with a distinct halo feature and streamers descending down to an altitude of approximately 48 km, the sprite current signal identified in the electric sferic, measured at a range of about 1,110 km, peaked at approximately 1 ms after the return stroke.展开更多
In order to expand the color-change range and make the discoloration temperature suitable for the daily textiles,a new formulation of mixed-colorants thermochromic core material is designed,in which crystal violet lac...In order to expand the color-change range and make the discoloration temperature suitable for the daily textiles,a new formulation of mixed-colorants thermochromic core material is designed,in which crystal violet lactone(CVL)is the basic color former,bisphenol A(BPA)is the developer,especially the solvent-based dye and dodecyl dedecanoate are used as the extended dye and the solvent,respectively.Scanning electron microscope(SEM),differential scanning calorimeter(DSC)and thermogravimetric analyzer(TGA)were applied to study the morphology,encapsulation rate,non-isothermal crystallization behavior and thermal stability of the mixed-colorant thermochromic microcapsules(MCTMs)prepared by in-situ polymerization.The results show that MCTMs have good sphericity,uniform particle size,good thermal stability and the encapsulation rate can reach 86.73%.Under the non-isothermal conditions,the encapsulation of formaldehyde-melamine resin wall material can slightly reduce the crystallization rate of the solvent,but does not affect the relative crystallinity,thermal properties and discoloration sensitivity of the core materials.With the variety of ambient temperatures in the range of 20–35℃,the printed cotton fabrics with MCTMs could change color reversibly between different tones with good reliability and durability,and exhibit more gorgeous colors than the common thermochromic materials.展开更多
Patterned photonic crystals with structural colors on textile substrates have attracted a special attention due to the great advantages in application,which currently become a research hot-spot.This study utilized an ...Patterned photonic crystals with structural colors on textile substrates have attracted a special attention due to the great advantages in application,which currently become a research hot-spot.This study utilized an ink-jet printing technology to prepare high-quality photonic crystal patterns with structural colors on polyester substrates.The self-assembly temperature of poly(styrene-N-methylol acrylamide)(P(St-NMA))microspheres set to construct photonic crystals were deeply optimized.Moreover,the structural colors of prepared photonic crystal patterns were characterized and evaluated.When the mass fraction of P(St-NMA)microspheres was 1.0 wt.%,the pH value ranged from 5 to 7,and the surface tension was in the range of 63.79 to 71.20 mN/m,inks could present the best print performance.At 60°C,prepared P(St-NMA)microsphere inks were good for printing to obtain patterned photonic crystals with regular arrangement and beautiful structural colors.Specifically,photonic crystals with different colors could be constructed by regulating the diameter of microspheres in inks,and prepared structural colors exhibited distinct iridescent phenomenon.The present results could provide a theoretical basis for the industrial realization of patterned photonic crystals by ink-jet printing technology.展开更多
基金supported by the National Key Basic Research and Development Program (2017YFC1501501)National Natural Science Foundation of China (41574179, 41875006)+4 种基金National Natural Science Foundation for Excellent Youth of China (41622501)"The Hundred Talents Program" of Chinese Academy of Sciences (2013068)supported by funding from the NOAA Office of Global Programs for the Global Precipitation Climatology Project (GPCP)by NASA via the Tropical Rainfall Measuring Mission (TRMM)supported by NASA's HQ Earth S cience Data Systems (ESDS) Program
文摘The triangulation of red sprites was obtained, based on concurrent observations over a mesoscale convective system(MCS) in North China from two stations separated by about 450 km. In addition, broadband sferics from the sprite-producing lightning were measured at five ground stations, making it possible to locate and identify the individual causative lightning discharges for different elements in this dancing sprite event. The results of our analyses indicate that the sprites were produced above the trailing stratiform region of the MCS, and their parent strokes were located mainly in the peripheral area of the stratiform. The lateral offset between sprites and causative strokes ranges from a few km to more than 50 km. In a particularly bright sprite, with a distinct halo feature and streamers descending down to an altitude of approximately 48 km, the sprite current signal identified in the electric sferic, measured at a range of about 1,110 km, peaked at approximately 1 ms after the return stroke.
基金supported by the National Natural Science Foundation of China(grant No.22075252)the Key Program for International S&T Innovation Cooperation Projects of China(project No.2022YFE0125900).
文摘In order to expand the color-change range and make the discoloration temperature suitable for the daily textiles,a new formulation of mixed-colorants thermochromic core material is designed,in which crystal violet lactone(CVL)is the basic color former,bisphenol A(BPA)is the developer,especially the solvent-based dye and dodecyl dedecanoate are used as the extended dye and the solvent,respectively.Scanning electron microscope(SEM),differential scanning calorimeter(DSC)and thermogravimetric analyzer(TGA)were applied to study the morphology,encapsulation rate,non-isothermal crystallization behavior and thermal stability of the mixed-colorant thermochromic microcapsules(MCTMs)prepared by in-situ polymerization.The results show that MCTMs have good sphericity,uniform particle size,good thermal stability and the encapsulation rate can reach 86.73%.Under the non-isothermal conditions,the encapsulation of formaldehyde-melamine resin wall material can slightly reduce the crystallization rate of the solvent,but does not affect the relative crystallinity,thermal properties and discoloration sensitivity of the core materials.With the variety of ambient temperatures in the range of 20–35℃,the printed cotton fabrics with MCTMs could change color reversibly between different tones with good reliability and durability,and exhibit more gorgeous colors than the common thermochromic materials.
基金We were sincerely grateful to the financial support from the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LQ19E030022 and LY20E030006)the National Natural Science Foundation of China(Grant No.51773181)+3 种基金the Research Startup Fund of Zhejiang Sci-Tech University(Grant No.18012212-Y)the Opening Project of Key Laboratory of Clean Dyeing and Finishing Technology of Zhejiang Province(Project Number:1802)the Basic Public Welfare Research Project of Zhejiang Province(Grant No.LGC20E030001)the Fund for the Excellent Doctoral Program of Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology in Zhejiang Sci-Tech University(CETT2017001).
文摘Patterned photonic crystals with structural colors on textile substrates have attracted a special attention due to the great advantages in application,which currently become a research hot-spot.This study utilized an ink-jet printing technology to prepare high-quality photonic crystal patterns with structural colors on polyester substrates.The self-assembly temperature of poly(styrene-N-methylol acrylamide)(P(St-NMA))microspheres set to construct photonic crystals were deeply optimized.Moreover,the structural colors of prepared photonic crystal patterns were characterized and evaluated.When the mass fraction of P(St-NMA)microspheres was 1.0 wt.%,the pH value ranged from 5 to 7,and the surface tension was in the range of 63.79 to 71.20 mN/m,inks could present the best print performance.At 60°C,prepared P(St-NMA)microsphere inks were good for printing to obtain patterned photonic crystals with regular arrangement and beautiful structural colors.Specifically,photonic crystals with different colors could be constructed by regulating the diameter of microspheres in inks,and prepared structural colors exhibited distinct iridescent phenomenon.The present results could provide a theoretical basis for the industrial realization of patterned photonic crystals by ink-jet printing technology.
